Chapter 17: In-Stent Restenosis

PATIENT CASE

A 67-year-old man with a past medical history significant for insulin-dependent diabetes mellitus, hypertension, and coronary artery disease was admitted with typical angina (Canadian Cardiovascular Society [CCS] class III) for 1 month. The patient had a history of acute non–ST-segment elevation myocardial infarction (NSTEMI) 12 months prior to his presentation and was treated with a total of 5 drug-eluting stents in the left anterior descending (LAD), left circumflex (LCx), and right coronary (RCA) arteries. The patient was compliant with dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI). During the current admission, the patient had dynamic electrocardiogram (ECG) changes in anterolateral leads with elevated troponin I. Echocardiography revealed a hypokinetic left ventricular (LV) apex with estimated left ventricular ejection fraction (LVEF) of 45%. The patient underwent coronary angiogram that showed severe diffuse in-stent restenosis (ISR) in the proximal LAD stent and moderate ISR in the diagonal stent (bifurcation lesion) along with significant ostial disease in the LAD extending from the upper edge of the LAD stent. Kissing balloon inflations were performed using a 2.5 × 15 mm sapphire noncompliant (NC) balloon in the LAD and a 2 × 10 mm sapphire balloon in the diagonal branch. Keeping the guidewire in the LAD, the LCx was wired using a BMW guidewire. A Xience V (Abbott, Chicago, IL) 2.75 × 12 mm stent was positioned in the ostioproximal LAD overlapping the distal stented segment (see Figure 17-3, red arrow) and deployed at 18 atm, keeping an uninflated 2 × 10 mm sapphire balloon in the distal left main and ostial LCx. The overlapped segment was postdilated using the same in-stent balloon at 20 atm. Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow was achieved in the LAD without any compromise of ostial LCx.

INTRODUCTION

Over the course of the past 3 decades, PCI with stent implantation transformed the practice of cardiology as it became the most widely performed procedure for the treatment of symptomatic coronary artery disease (CAD).¹ The most common complication of metallic stents is in-stent restenosis (ISR), which results in renarrowing of the arterial lumen and can lead to serious clinical events such as the need for reintervention and onset of acute coronary syndrome, including myocardial infarction. Since the introduction of metallic stents to clinical practice, clinicians, scientists, and engineers have studied the mechanism of ISR and searched for solutions to minimize or eliminate it. The development of drug-eluting stents (DES) was a breakthrough because they had a reduced ISR rate compared with bare metal stents (BMS).² As a result, DES became the default stent for the treatment of CAD, and research efforts were shifted to prevention and treatment of DES-related ISR. The problem of late restenosis as a result of neoatherosclerosis has also emerged, adding to the complexity and challenge of the treatment of ISR. In 2017, the focus is now targeted on reducing the rate of ...